The map shows the mean annual concentration of nitrates (NO3), expressed as milligrams of NO3-N per litre of water, observed in groundwater monitoring stations and reported by EEA member countries via WISE. The purpose of the map is to provide an overview of the mean annual value of nitrates in groundwater across Europe and to enable the user to compare values per country or per groundwater body, depending on the scale of visualisation. Historical data since 2000 can be displayed using the time slider, and different horizons can be selected using the layers menu.

The map shows the mean annual concentrations of nitrites (NO2), expressed as milligrams of NO2-N per litre of water, observed in groundwater monitoring stations and reported by EEA member countries via WISE. The purpose of the map is to provide an overview of the mean annual value of nitrites in groundwater across Europe and to enable the user to compare values per country or per groundwater body, depending on the scale of visualisation. Historical data since 2000 can be displayed using the time slider, and different horizons can be selected using the layers menu.

The data series are calculated as the average of annual mean concentrations for groundwater bodies/river stations/lake stations in Europe. Only complete series after inter/extrapolation are included (see indicator specification). The number of groundwater bodies/river stations/lake stations included per country is given in the notes below the individual substance charts.

Following the principles of the European Thematic
Strategy on the Protection and Conservation of
the Marine Environment, the collective interest
of EEA and UNEP/MAP has been developed
towards a product focusing on priority pollution
zones in the Mediterranean Sea and addressing
emerging issues. All these issues come under the
prism of an ecosystem approach. The core of this
report derives from the latest (2003–2004) country
National Diagnostic Analyses reports (NDA).

Soil contamination requiring clean up is present at approximately 250000 sites in the EEA member countries, according to recent estimates. And this number is expected to grow. Potentially polluting activities are estimated to have occurred at nearly 3 million sites (including the 250000 sites already mentioned) and investigation is needed to establish whether remediation is required. If current investigation trends continue, the number of sites needing remediation will increase by 50% by 2025. By contrast, more than 80000 sites have been cleaned up in the last 30 years in the countries where data on remediation is available. Although the range of polluting activities (and their relative importance as localised sources of soil contamination) may vary considerably across Europe, industrial and commercial activities as well as the treatment and disposal of waste are reported to be the most important sources. National reports indicate that heavy metals and mineral oil are the most frequent soil contaminants at investigated sites, while mineral oil and chlorinated hydrocarbons are the most frequent contaminants found in groundwater. A considerable share of remediation expenditure, about 35% on average, comes from public budgets. Although considerable efforts have been made already, it will take decades to clean up a legacy of contamination.